Pressure-gage



Paserlced Dec. 8,'1891l (No Model.)

lT. A. MASTERS.

PRESSURE GAGE.

UNTT-nn STATns PATENT Orrrcn.

THOMAS MASTER-AOF CHICAGO, ILLINOIS.

PRESSURE-GAGE.

SPECIFICATION forming part of Letters Patent No. 464,576, dated December 8, 1891.

Y Application filed August 18. 1890. Serial No. 362.347. (No model.)

T0 all whom, t may concern:

Be it known that I, THOMAS A. MASTERS, a citizen of the United States, residing at Chicago, in the county ot Cook and State of Illinois, have invented certain new and use- Figure l is an elevation showing the gagel attached ready for use. Fig. 2 is a longitudinal section w-ith the mercury lowered and not in use. Fig. 3 is a longitudinal section with the mercury raised as in use.

This invention relates to mercury-gages for testing as to leakage, and is especially designed for the use ofv gas-ftters in testing the pipes as to whether they are perfectly sealed, but can be used byothers than gas-itters, and for other uses and purposes.

The object of the invention is to construct a mercury-gage which will be very sensitive and at the same time reliable and safe in use,

and which will be always in condition for use,

and will be light and strong and can be carried around without any liability of spilling or losing the mercury; and to this end it consists, essentially, of an elastic receptacle for the 1nercury,which will compress under pressure and raise the mercury and will return to its normal condition when Ithe pressure is removed, allowing the mercury to drop.

rlhe invention further consists in the combination of such elastic receptacle with a sight and inclosin g casin g, as hereinafter more particularly described, and pointed out in the claims. f

In the drawings, A represents the receptacle for the mercury, made of india-rubber or other elastic material possessing the nature or quality of being compressible under pressure and assuming its normal shape and condition when the pressure is removed. This receptacle is of a bulb shape shown, or other bulb shape, which will respond readily and quickly to pressure and will be equally as sensitive in assuming its natural shape with the removal of the pressure, and will also show depreciation or reduction of the'pressure. As shown,

the receptacle A has'a pear-shaped bulb or body port-ion a, and a contracted neck a; but the bulb shape of the body a and the shape of the neck a could be otherwise formed, so long as they furnished a bulb-bodyand a contracted neck operating to draw around and make an air-tight joint.

B is a glass tube, to the inner end of which' the receptacle A is attached by the end ofthe tube B entering the neck a for the neck to tightly clasp around the tube, or in any other -suitable manner, that will form an air-tight ing C, screw-threaded or otherwise removably attached to the casing. y

E is a head or base for the inner end ofthe casing D, and this head or base can be formed with the case or be a separate piece screwthreaded or otherwise attached to the end of the case C'. This head or base has a neck or annular flange e, screw-threaded, as shown, on its exterior, but which could be screwthreaded on its interior, and the inner end ot' the sight-tube extends into or below the end of `this neck e.` This head or base can be made of brass or other suitable material.

F is a cup surrounding the mercury-receptacle A and attached to the head of the base E, and, as shown, the cup at its inner end is screw-threaded to receive the exterior screwthread ot' the 'neck or flange e; but it the neck or flange had an interior screw-thread the end ofthe cup would have a corresponding exterior screw-thread. This cup F can be made of brass or other suitable material and can be of the shape shown or other shape that will inclose and surround t-he receptacle A, and it has a stud or extension f with an exterior screw-thread for the attachment of the gage, which stud has a longitudinal hole g, communicating with the interior of the receptacle A.

IOO

G is an ordinary T-coupling, to one end of which the gage is attached by the stud or extensionf, as shown in Fig. 1.

H is the projecting or cap end of a gaspipe to which another end of the T-coupling G is attached, as shown in Fig. l.

I is a hose attached to the third end of the T-coupling and leading to an air-pump and having on its coupling end a shut-off valve or cock z'.

The parts of the gage are assembled by screwing or otherwise securing together the.

casing C and head or base E. The receptacle A is attached to the sight-glass B by slipping its neck onto the end of the sight-glass and the sight-glass inserted in the casing C and head or base E and there secured. For the body d of the receptacle to lie below the neck or flange e the cap D is placed en the end of the casing C, and the cup F, with its studf, attached to the head or base E to surround and inclose the receptacle A, when the device is ready for use.

In use a T-coupling is screwed at one end onto the projecting end of a gas-tube when the gage is used by gas-titters, so as to have the end of the T for the attachment of the gage Vertical. The gage as a Whole is attached to its T and by screwing the stud extension f into the end, and the tube I from the air-pump is attached to its end of the T, connecting the gas-pipe, the gage, and the air-pump together. rlhe pum p is then worked, forcing air into the gas-pipes and also to a corresponding pressure into the cup F around the receptacle, and such pressure will act on the receptacle and compress it, forcing the mercury out into the sight-tube B, in which it will gradually rise, and when the desired pressure is reached a stop-cock or other shut-OHL' is turned, closing the inlet of air from this airpump and holding the pressure in the gas pipe and gage. The mercury in the sightglass will remain at the same height if there is no leak in the gas-pipe; but if there is a leak in the pipes such leak is at once detected, as the air escaping from the pipes at the leak will reduce the pressure in the cup F around the receptacle A, and the receptacle will fill ont, causing the mercury to descend,

thus indicating a leakage at some point inthe pipes, and such leakage can be found and stopped and the air-pump again Worked, and such operations can be repeated until the mercury holds steady, showing that the pipes are all right. The pressure in the pipes is then released, releasing the pressure in the cup F, and with such release of the pressure the receptacleA assumes its normal condition and the mercury descends into the receptacle, where it is held for the test of other pipes.

The gage is very simple in construction, can be readily attached and detached, can be easily carried, and in carrying will not become disarranged, as the mercury remains in its receptacle unless forced out by pressure, will always be ready for use, and will be found perfectly correct and reliable in use; and it is to be understood that the essential feature in carrying out the invention is lthe elastic receptacle A, by which the mercury is held and actuated by a differential pressure on the receptacle.

Vhat I claim as new, and desire to secure by Letters Patent, is-

l. The elastic compressible receptacle A, having the pear-shaped body a, containing mercury, and neck a', sight-glass B, tightly compressed by the neck a to form an airtight connection with the receptacle A, casing C, inclosing the sight-glass B, and cap D, in combination with the head E for the passage of the sight-glass B and attachment of the casing C, and cup F, surrounding and tightly inclosiug the receptacle A and attached to the head E, substantially as and for the purposes specified. Y

2. The elastic compressible,receptacle A, having the pear-shaped body a., containing mercury, neck a', and sight-glass B, tightly compressed by the neck a', in combination with the head E for the passage of the sightglass B, and the cup F, surrounding and tightly inclosing the receptacle A and at` tached to the head E, substantially as and for the purposes specified.

THOMAS A. MASTERS.

Witnesses: l

JNO. C. MAcGREeoR, S. E. HURLBUT. 

